The present invention relates to dry powder inhalers and more exactly to a foil cutter device for accessing a sealed dose onto a dosing member carrying one or several pre-metered powder doses for a dry powder inhaler.
Today supply and distribution of medical powders take place in many different ways. Within health care more and more is focussed on the possibility to dose and distribute powder directly to the lungs of a user by means of an inhaler to obtain an efficient, fast, and user friendly administration of the specific medical substance.
Inhalers have been developed from being very simple to the up-to-date relatively complicated devices. For the up-to-date inhalers some form of dosing process is almost entirely used for preparing the dose to be inhaled. Most often the dosing of the amount to be inhaled takes place industrially in advance in a dose package containing of the order 10-50 doses. The inhaler then is loaded with this dose package as the source of each dose. Other inhalers have a magazine from which the powder is dosed by some device for distribution to the inspiration air. In both cases the powder will generally be strongly agglomerated and therefore must be dispersed.
When it comes to a dry powder inhaler (DPI) one aspect that is of great importance is to keep the medical substance free from air humidity, dirt, or any other kind of pollution. In order to achieve this, the dose of powder needs to be kept in a sealed volume during storage and preferably, for as long as possible until the dose on a carrier element is to be inhaled. The material, used for sealing the dose may be for instance aluminum or some polymer foil. Such a foil should prevent all kind of leakage from the surrounding environment, both when it comes to penetration of the film as such, as well as a leakage between the foil and the edge walls of the carrier element to which the foil is fixed, e.g. by a welding or gluing process.
Therefore there is a demand for a device, which will prepare the dosing member for an immediate access to its pre-metered dose of the medical powder at the proper time in connection to an inhalation process for releasing a certain dose of the medical powder dispensed by the DPI.
A dosing cassette or the like will in a typical embodiment carry a number of prepared doses, which for protection of the medical powder are covered by a metallic or plastic foil. The foil-cutter device of the present invention provides a tool for accessing a sealed dose of medical powder of the cassette, which is placed into a dry powder inhaler (DPI). When a user inhales through the DPI the foil-cutter will open the foil for access to a pre-metered powder dose. The foil-cutter arrangement ensures that no access is permitted to the pre-metered dose during any other circumstances. Particularly the present invention is adapted to be applied in an inventive continuous inhaler prolonging the release of a powder dose during an inhalation.